This invention is concerned with a method of and machine for automatically determining coordinates of an operating path of an adhesive-applying nozzle of an adhesive applicator device for a shoe machine using an optical sensing head which is guided along the operating path by advancing movement along two coordinate axes under the control of a guidance system, wherein for each step of movement along one of said coordinate axes the coordinate axis value thereof and also the corresponding coordinate axis value along the other coordinate axis are determined and stored.
One adhesive applicator device for use in a shoe machine, namely a cement lasting machine, is disclosed in U.S. patent specification No. 440,7033 and comprises two adhesive-applying nozzles operating along opposite sides of a shoe bottom. For thus moving the nozzles numerically controlled stepping motors are provided, themselves controlled by a computer to which the individual coordinate axis values for the movement of the nozzles are supplied.
For determining these coordinate axis values, a procedure is disclosed in European Patent Specification No. 0084949, in accordance with which a transparent sheet provided with a coordinate grid is laid on the insole of the shoe so that the contours of the latter can be seen through the sheet. On the coordinate grid the particular coordinate axis values for the operating path of the adhesive-applying nozzles along the opposite sides of the shoe bottom are read off and manually inputted into the memory of the aforementioned computer.
In addition, where it is desired automatically to guide a sensing head along a path and convert discrete coordinates of points along said path into digital values, it is known, e.g. from U.S. patent specification No. 3,624,283, to move the sensing head along two mutually perpendicular coordinate axes, the head recognising the path by optical means which is effective to control stepping motors for the two coordinate axes in such a manner that the sensing head follows the path. In this case coordinate axes values are determined which indicate the particular coordinates of the sensing head. These coordinate axis values can for example be supplied to a punched tape for subsequent utilisation.